JPH08301668A - Suppressant for slaking - Google Patents

Abstract

PURPOSE: To prepare a chemical capable of suppressing hydrating actions occurring when using a basic aggregate as an aggregate for a monolithic refractory and suppressing slaking of the refractory such as cracking. CONSTITUTION: This suppressant for slaking comprises a glycolic acid/aluminum lactate compound or a citric acid/aluminum lactate compound. The hydration occurring when using a basic aggregate can be suppressed by using the compound to suppress the slaking caused by the hydration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an anti-slaking agent, and more specifically, it suppresses the digestive action mainly occurring when a basic aggregate is used as an aggregate of an irregularly shaped refractory, and cracks the refractory. It is intended to provide a drug for suppressing slaking such as occurrence.

[0002]

2. Description of the Related Art In the steel industry, irregular shaped refractory has many advantages such as easy construction and labor saving because it can be molded into an arbitrary shape. Shows.

Currently available amorphous refractories include castables, spraying materials, ramming materials, stamping materials, coating materials, slinger materials, and the like. Aggregates used for these are silica, zircon, and alumina. There are neutral or acidic aggregates such as quality, graphite and silicon carbide. In addition, compared to such neutral or acidic aggregates, basic aggregates such as magnesia and dolomite are widely used in the field of standard refractories because of their excellent corrosion resistance, but irregular refractory When this is used for the product, a part of the aggregate is digested by the addition of water used in the production of the amorphous refractory, and this digestion is further promoted during heating and drying, resulting in the formation of hydroxide. It causes volume expansion of the refractory material. Therefore, as a result, cracks occur in the refractory construction body,
Since the construction body is fragile, it cannot be used as a refractory.

In order to suppress the digestion of the basic aggregate, that is, the hydration reaction, many methods have been proposed in the past. For example, a method using paraffin, asphalt, pitch, oils, resins, oxycarboxylic acids or salts thereof, sucrose, etc., or a method using a sparingly soluble phosphate (JP-A-61-291465), amorphous. Method using fine silica powder (JP-A-58-99177), method using borax, boric acid
(JP-A-57-129881), a method of using a magnesia aggregate containing a specific amount of CaO component and Al ₂ O ₃ component (JP-A-5-70247)
No.) etc. have been proposed.

However, each of these methods
Not only has many problems such as contamination of molten metal, low-melting point substance generated in refractory, low strength, poor corrosion resistance of refractory, poor volume stability, etc. The effect of is not yet sufficient. Further, a method of using a polyvalent metal salt of an organic acid such as citric acid, lactic acid, glycolic acid, tartaric acid or acetic acid as a digestive inhibitor has been proposed, but similarly, the digestive inhibitory effect is still insufficient.

[0006]

SUMMARY OF THE INVENTION Accordingly, the present inventors
We have diligently studied a method of suppressing digestion that occurs when basic aggregate is used and suppressing slaking that occurs due to digestion. As a result, by using a glycolic acid / aluminum lactate compound or a citric acid / aluminum lactate compound, it was found that such a material has an excellent effect of suppressing slaking, and the present invention is completed based on such findings. It came to.

[0007]

That is, the present invention relates to an anti-slaking agent comprising a glycolic acid / aluminum lactate compound, and further to an anti-slaking agent comprising a citric acid / aluminum lactate compound.

[0008]

The operation of the present invention will be described in more detail below. Glycolic acid / aluminum lactate compound of the present invention (hereinafter referred to as glycolic acid / aluminum lactate)
Alternatively, a citric acid / aluminum lactate compound (hereinafter referred to as a citric acid / aluminum lactate compound) can be produced by the following method. That is, first, a water-soluble aluminum salt such as aluminum chloride, aluminum sulfate, aluminum nitrate or basic aluminum chloride is reacted with a carbonate or bicarbonate of an alkali metal or ammonium to obtain an alumina hydrate. Then, the alumina hydrate can be dissolved in a mixed acid of glycolic acid and lactic acid or dried to obtain glycolic acid / aluminum lactate. Further, citric acid / aluminum lactate can be obtained by using a mixed acid of citric acid and lactic acid as the mixed acid.
Alternatively, it can also be produced by adding glycolic acid or citric acid to basic aluminum lactate.

In the present invention, it is particularly important that such glycolic acid / aluminum lactate or citric acid / aluminum lactate is a simple mixture of aluminum glycolate and aluminum lactate, or aluminum citrate. The use of a simple mixture with aluminum lactate is not clear for the reason, but the effect of the anti-slaking agent of the present invention cannot be expected.
The present invention can achieve its effect for the first time by the above-mentioned means, that is, by producing a solution as a starting material.

With respect to the mixing ratio of the raw materials of glycolic acid / aluminum lactate of the present invention, the glycolic acid and aluminum constituting the glycolic acid / aluminum lactate have a glycolic acid / Al ₂ O ₃ molar ratio of 0.3 to 6.0. Yes, lactic acid and aluminum have a lactic acid / Al ₂ O ₃ molar ratio of 0.3-
It is in the range of 6.0, and the total amount of glycolic acid and lactic acid is in the range of 1.0 to 8.0 in terms of (glycolic acid + lactic acid) / Al ₂ O ₃ molar ratio. Regarding the mixing ratio of the raw materials of citric acid / aluminum lactate, the citric acid and aluminum constituting citric acid / aluminum lactate are citric acid / Al ₂ O ₃
The molar ratio is in the range of 0.1 to 2.0, lactic acid and aluminum are in the lactic acid / Al ₂ O ₃ molar ratio of 0.3 to 6.0, and the total amount of citric acid and lactic acid is (citric acid + lactic acid). / Al ₂ O ₃
The molar ratio is in the range of 0.8 to 7.0. When used in such a blending ratio, the anti-slaking agent of the present invention is most effective. That is, in the blending ratio of these raw materials, if the total amount of the above-mentioned organic acid is much larger than that of aluminum normal salt, the reaction between the basic aggregate and the organic acid becomes violent, which is not practical, and vice versa. When the amount of the organic acid is too small, the stability of the aluminum salt deteriorates, and as a result, the solubility of the aluminum salt decreases and the digestion suppressing effect also decreases, which is not preferable.

The glycolic acid / aluminum lactate or citric acid / aluminum lactate of the present invention may be used in the form of a solution as described above, but any solution such as spray drying, aeration drying, vacuum drying or freeze drying may be used. You may dry and use by a drying means.

With respect to the amount of glycolic acid / aluminum lactate or citric acid / aluminum lactate used as a slaking inhibitor, it is generally 0.05 to 10 parts by weight, preferably 1 to 5 parts by weight based on the amount of basic aggregate used. Mix in the range of parts. That is, when the amount is 0.05 parts by weight or less, the effect of suppressing the slaking of the present invention is not sufficiently exhibited, and even when 10 parts by weight or more is compounded, the effect equivalent to the compounding amount cannot be expected, which is not economical. Furthermore, although the slaking inhibitors of the present invention may be used alone, they may be mixed and used, or may be used in combination with other additives such as a dispersant.

The types of basic aggregates targeted by the anti-slaking agent of the present invention include magnesia aggregates such as electrofused magnesia, seawater magnesia, and natural magnesia, spinel aggregates, magnesia chromium aggregates, dolomite bones. Wood, calcia aggregate and the like.

The method of using the anti-slaking agent of the present invention is to thoroughly mix such a basic aggregate with glycolic acid / aluminum lactate or citric acid / aluminum lactate, and then add a hardening agent such as alumina cement. The method of adding and mixing is preferable in that the digestive inhibitory effect can be best exhibited. However, after mixing the slaking inhibitor of the present invention with a hardening material or another refractory material, this may be added to and mixed with the basic aggregate, and the hardening material such as the basic aggregate and alumina cement or other refractory material. After mixing and, the anti-slaking agent of the present invention may be mixed. However, these are merely examples, and the present invention is not particularly limited to such usage.

When the slaking inhibitor of the present invention is used, various acidic aggregates, neutral aggregates or carbon can be used together with the basic aggregate. Furthermore, monoethanolamine for the purpose of adjusting the working time,
Alkanolamines such as triethanolamine, diethanolamine and ethylenediamine, and chelating agents such as EDTA and amino acids may be used in combination. In addition, chromic acid, aluminum phosphate, aluminum sulfate as a binder,
Water glass, various sols and the like can also be used together. Further, in order to exert the effect of the present invention, a polymer dispersant, a dispersant such as a phosphate dispersant, an alumina powder, a silica flower, an ultrafine powder such as zircon flour are used together, or a sparingly soluble phosphate or Amorphous silica powder can also be used in combination.

[0016]

EXAMPLES Examples of the present invention will be described below for further explanation.
All percentages are by weight unless otherwise specified.

Example 1 Basic Aluminum Lactate Solution
(Lactic acid / Al ₂ O ₃ molar ratio 3.0, Al ₂ O ₃ concentration 5.0%) 1000 g and 70% glycolic acid solution 159.8 g were mixed to form a mixed solution.
After holding for 2 hours, powder was obtained by spray drying. This powder has a glycolic acid / Al ₂ O ₃ molar ratio of 3.0, a lactic acid / Al ₂ O ₃ molar ratio of 3.0, and (glycolic acid +
Lactic acid) / Al ₂ O ₃ molar ratio of 6.0 was glycolic acid / aluminum lactate powder, which was used as a slaking inhibitor.

[0018] As an aggregate, a magnesia aggregate (particle diameter of 3 mm or more
25.7%, 1 to 3 mm28.6%, 0.088 to 1 mm17.1%, 0.088 mm or less 28.6%) 100 parts by weight and the above-mentioned slaking inhibitor are well mixed at the ratio shown in Table 1 and used as a curing material. 5 parts by weight of alumina cement was added and mixed, a predetermined amount of water was added and kneaded, and the mixture was poured into a 2 × 2 × 8 cm mold and vibration-molded. This was cured at 20 ° C. for 24 hours and then demolded to obtain a molded body.

The slaking test was carried out at 150 ° C.
Under saturated water vapor (5 kgf / cm ² ) for 7 hours. In addition, the strength of the molded body was measured by heat-treating the molded body that was subjected to the slaking test and the molded body that was not subjected to the slaking test at 110 ° C for 24 hours, cool them to room temperature, and then use a universal strength tester. The dry bending strength was measured. The evaluation of the slaking test is shown by the slaking test evaluation reference values shown in Table 2. Table 1 shows the test results.

[0020]

[Table 1]

[0021]

[Table 2]

The strength of the molded product, which was composed of glycolic acid / aluminum lactate powder but did not contain the slaking inhibitor of the present invention, could not be measured because it collapsed in the slaking test. Also, as is clear from the results in Table 1,
The anti-slaking effect by the addition of the anti-slaking agent of the present invention is clear, and the strength of the molded article added with the anti-slaking agent after the slaking test is expected to be significantly higher than that of the molded article not subjected to this test. It has an impossible effect.

Example 2 To 600 g of aluminum chloride, 1278 g of ammonium carbonate was added and reacted, and the product was filtered and washed with ion-exchanged water to form an alumina hydrate.
1000 g of (Al ₂ O ₃ 20%) was obtained. This alumina hydrate was then dissolved in a mixed acid of glycolic acid and lactic acid,
After holding for 5 hours, powder was obtained by spray drying. Separately, this alumina hydrate was dissolved in a mixed acid of citric acid and lactic acid to obtain a powder in the same manner. By changing the mixing ratio of glycolic acid and lactic acid or citric acid and lactic acid, respectively, glycolic acid-aluminum lactate powder and citric acid-aluminum lactate powder having different component compositions are obtained as a slaking inhibitor. The same test as in Example 1 was carried out.

[0024] As an aggregate, a magnesia aggregate (particle diameter of 3 mm or more
25.7%, 1 to 3 mm28.6%, 0.088 to 1 mm17.1%, 0.088 mm or less 28.6%) 100 parts by weight and 1 part by weight of the slaking inhibitor of each composition shown in Table 3 are mixed well, and As a hardening material, 5 parts by weight of alumina cement was added and mixed, a predetermined amount of water was added and kneaded, and the mixture was poured into a 2 × 2 × 8 cm mold and vibration-molded. This was cured at 20 ° C. for 24 hours and then demolded to obtain a molded body.

For the slaking test, this molded product was heated to 150 ° C.
Under saturated water vapor (5 kgf / cm ² ) for 7 hours. In Table 3, composition a is the molar ratio of glycolic acid / Al ₂ O ₃ , b is the molar ratio of citric acid / Al ₂ O ₃ , and c is lactic acid / A.
represents the molar ratio of l ₂ O ₃ , where x is (glycolic acid + lactic acid) / Al ₂ O ₃
And y represent the molar ratio of (citric acid + lactic acid) / Al ₂ O ₃ respectively. For comparison, another organic aluminum oxide powder was used in place of the slaking inhibitor of the present invention, and the same test was conducted. In addition, the slaking test evaluation is
The reference values in Table 2 are shown.

[0026]

[Table 3]

(Example 3) As a slaking inhibitor of the present invention, glycolic acid / aluminum lactate has a glycolic acid / Al ₂ O ₃ molar ratio of 3.0, lactic acid / Al ₂ O ₃ mol 3.0, and (glycolic acid + lactic acid). / Al ₂ O ₃ using those molar ratios 6.0 and citric acid lactic aluminum citrate / Al ₂ O ₃ molar ratio
1.0, lactic acid / Al ₂ O ₃ mol 3.0, and (citric acid + lactic acid) / Al ₂ O ₃
A slaking suppression test was conducted using a material having a molar ratio of 4.0. For comparison, a slaking suppression test was carried out using powders of normal salts of aluminum glycolate, aluminum citrate and aluminum lactate instead of the slaking suppressor of the present invention.

[0028] Dolomite aggregate (particle size of 3 mm or more as an aggregate
36.5%, 1-3 mm 40.0%, 0.088-1 mm 23.5%) 70 parts by weight,
20 parts by weight of magnesia aggregate (particle diameter 0.088 mm or less) and 10 parts by weight of magnesia ultrafine aggregate (particle diameter 1 μm or less) were mixed well with the prescribed amount of each additive shown in Table 4 and cured. 5 parts by weight of aluminum phosphate and lignin sulfonic acid-based dispersant that are neutralized as materials to ensure workability
After 0.5 part was added and mixed, 8 parts by weight of water was further added and kneaded, and the mixture was poured into a 2 × 2 × 8 cm mold and vibration-molded. This was cured at 20 ° C. for 24 hours and then demolded to obtain a molded body. The slaking test was carried out by allowing the molded body to stand under saturated steam at 130 ° C. (3 kgf / cm ² ) for 3 hours.
The slaking test was evaluated according to the criteria shown in Table 2, and the results are shown in Table 4.

[0029]

[Table 4]

[0030]

INDUSTRIAL APPLICABILITY In a refractory material, as various binders,
For example, water glass, clay, sodium phosphate, aluminum phosphate, cement, alumina cement or hydraulic alumina, sodium aluminate, alumina sol, silica sol, amine silicate, various resins and the like are used.
Among them, alumina cement, when using hydraulic alumina such as γ-alumina or ρ-alumina as a binder, a large amount of water is used as compared with the use of other binders,
The use of such water promotes local digestion of refractory materials and makes the construction body fragile. However, by using the anti-slaking agent of the present invention, such digestion is suppressed,
As a result, the strength of the construction body is improved, and it has an excellent effect as a slaking inhibitor. The anti-slaking agent of the present invention is most effective when used for forming and repairing steel containers such as a converter, a ladle, and a tundish.

Claims (4)

[Claims] 1. A slaking inhibitor comprising a glycolic acid / aluminum lactate compound. 2. The glycolic acid and aluminum constituting the glycolic acid / aluminum lactate compound have a glycolic acid / Al ₂ O ₃ molar ratio of 0.3 to 6.0, and lactic acid and aluminum have a lactic acid / Al ₂ O ₃ molar ratio. It is in the range of 0.3 to 6.0, and the total amount of glycolic acid and lactic acid is (glycolic acid +
The slaking inhibitor according to claim 1, wherein the molar ratio of lactic acid) / Al ₂ O ₃ is in the range of 1.0 to 8.0. 3. A slaking inhibitor comprising a citric acid / aluminum lactate compound. 4. The citric acid and aluminum constituting the citric acid / aluminum lactate compound have a citric acid / Al ₂ O ₃ molar ratio of 0.1 to 2.0, and the lactic acid and aluminum have a lactic acid / Al ₂ O ₃ molar ratio. It is in the range of 0.3 to 6.0, and the total amount of citric acid and lactic acid is (citric acid + lactic acid) / Al ₂ O ₃ molar ratio of 0.8.
The anti-slaking agent according to claim 3, which is in the range of from 7.0.